1. Field of the Invention
The present invention relates to an intake ducting device for a car engine, and especially to an air ducting device fixed in an intake tube, it is used for separating air flow against concentration when air flow in an air intake of a car passes the air ducting device.
2. Description of the Prior Art
For the purpose of helping an engine to get better air taking in effect, various vortex generators provided on the front ends of intake tubes have been developed in the markets for the purpose of making the air flow in the tubes on the front ends of the intake able to generate a vortex flowing in the type of whirling, such a vortex can render the air in a large amount flowing into the intake passes with high speed in type of whirling.
As shown in FIG. 1 depicting the structure of a vortex generator which is installed in a pipe line in front of an intake of an engine, the technical measure in construction of the vortex 20 generator is that, a round tube 90 with a larger diameter is provided with a central hollow pipe 91 with a smaller diameter, a plurality of curved blades 92 are provided between the round tube 90 and the central hollow pipe 91; thereby when air flows through the vortex generator, the central portion of the air passing the central hollow pipe 91 will generate a straight air flow, and the ambient air passing the curved blades 92 is divided into a plurality of volute airflows; the straight air flow and the volute air flows flowing separately are integrated into an air flow vortex after they leave the vortex generator.
As shown in FIG. 2, there is another vortex generator that can integrate and guide a plurality of volute air flows, structurally, the vortex generator has a round tube 90 provided therein with a central guiding post 93, and a plurality of curved blades 92 are provided between the round tube 90 and the central guiding post 93, the tailing end of the central guiding post 93 is conical, an end opening 94 is formed between the tailing ends of both the central guiding post 93 and the curved blades 92; thereby when air flows through the vortex generator, the air flow is divided to flow separately to the spaces among the curved blades 92 to form a plurality of volute air flows, and the volute air flows are primarily integrated by the function of the conical tailing end of the central guiding post 93.
In addition to the above stated two kinds of conventional vortex generators, other similar structures include: U.S. Pat. Nos. 5,113,838; 6,158,412 and 6,796,296 etc., whichever of the prior art is, the key point of designing is, to make air flow taken in be in the type of volute air flow; such mode of air intake might get the function of speeding up air intake, however it also has the defect of non uniform air intake.
Especially in this designing, gaps between every two neighboring blades are each in a flaring shape flaring outwards from the center of a vortex generator to show a state of gradually increasing the degree of flaring, that is, the gaps between every two neighboring blades become smaller and smaller in the direction away from the central point; hence when in taking in air, the wind resistance at a location near the center of a vortex generator is much larger than that far away from the center of a vortex generator, thereby air intake of the entire vortex generator is not uniform. If under such a non uniform air intake situation, a user adds air catalyst or some other combustion supporting material, for instance nitrogen oxide (N2O), at the intake end of an engine, this will render the catalyst or the combustion supporting material unable to uniformly diffuse. Moreover, by virtue that each blade of a conventional vortex generator has different curvature in extending outwards from the central point, they are more difficult for manufacturing.